Chapter 3 Cycles in Nature

Section 1 The Cycles of Matter

Section 2 Ecological Succession

Preview

Concept Mapping

Chapter 3 Section 1 The Cycles of Matter

Bellringer

What are the three different physical states in whichwater can commonly be found on Earth? Name oneway that you use water in each of these states inyour daily life.

Chapter 3

• Diagram the water cycle, and explain its importance to living things.

• Diagram the carbon cycle, and explain its importance to living things.

• Diagram the nitrogen cycle, and explain its importance to living things.

Objectives

Section 1 The Cycles of Matter

Chapter 3

• The movement of water between the oceans, atmosphere, land, and living things is known as the water cycle.

• How Water Moves During evaporation, the sun’s heat causes water to change from liquid to vapor.

• In the process of condensation, the water vapor cools and returns to a liquid state.

The Water Cycle

Section 1 The Cycles of Matter

Chapter 3

• The water that falls from the atmosphere to the land and oceans is called precipitation. Rain, snow, sleet, and hail are all forms of precipitation.

• Most precipitation falls into the ocean. • The precipitation that falls on the land and flows into

streams, rivers, and lakes is called runoff.

• Groundwater is precipitation that seeps into the ground and is stored between or within rocks. Groundwater slowly flows back into the soil, streams, rivers, and oceans.

The Water Cycle, continued

Section 1 The Cycles of Matter

Chapter 3

The Water Cycle

Section 1 The Cycles of Matter

Chapter 3

• Water and Life Without water, there would be no life on Earth. All organisms, from bacteria to animals and plants, are composed mostly of water.

• Water helps transport nutrients and waste within an organism.

• Water helps regulate temperature.

• All water taken in by an organism is eventually returned to the environment.

The Water Cycle, continued

Section 1 The Cycles of Matter

Chapter 3

• Besides water, the most common molecules in living things are molecules that contain carbon.

• The exchange of carbon between the environment and living things is known as the carbon cycle.

The Carbon Cycle

Section 1 The Cycles of Matter

Chapter 3

• Photosynthesis and Respiration During photosynthesis, plants use carbon dioxide from air to make sugars.

• Most animals get the carbon and energy they need by eating plants. Plants and animals break down sugar molecules to release energy in a process called respiration.

• Respiration uses oxygen and releases carbon dioxide and water back into the environment.

The Carbon Cycle, continued

Section 1 The Cycles of Matter

Chapter 3

• Decomposition and Combustions The breakdown of substances into simpler molecules is called decomposition.

• For example, when fungi and bacteria decompose organic matter, carbon dioxide and water are returned to the environment.

• Combustion is the process of burning a substance, such as wood or fossil fuels releases carbon.

The Carbon Cycle, continued

Section 1 The Cycles of Matter

Chapter 3

The Carbon Cycle

Section 1 The Cycles of Matter

Chapter 3

• Living things need nitrogen to build proteins and DNA.

• The movement of nitrogen between the environment and living things is called the nitrogen cycle.

The Nitrogen Cycle

Section 1 The Cycles of Matter

Chapter 3

• Converting Nitrogen Gas Although about 78% of the Earth’s atmosphere is nitrogen gas. Most organisms cannot use nitrogen gas directly.

• Bacteria in the soil are able to change nitrogen gas into forms that plants can use. This process is called nitrogen fixation.

• Other organisms get the nitrogen they need by eating plants or animals that eat plants.

The Nitrogen Cycle, continued

Section 1 The Cycles of Matter

Chapter 3

• Passing It On When organisms die, decomposers break down the remains.

• Decomposition releases a form of nitrogen into the soil that plants can use.

• Certain types of bacteria in the soil convert nitrogen to a gas, which is returned to the atmosphere.

The Nitrogen Cycle, continued

Section 1 The Cycles of Matter

Chapter 3

The Nitrogen Cycle

Section 1 The Cycles of Matter

Chapter 3

• Other forms of matter on Earth also pass through cycles. Many of the minerals that living cells need, such as calcium and phosphorous, are cycled through the environment.

• Each of the cycles is connected in many ways.

• Living organisms play a part in each of the cycles.

Many Cycles

Section 1 The Cycles of Matter

Chapter 3 Section 2 Ecological Succession

BellringerImagine that you have been hired to oversee the maintenance of a public forest. Answer the following questions to describe how you would approach the task:• How would you evaluate the health of the forest?• What actions would you take to keep the forest healthy?• What factors might pose a threat to the health ofthe forest? How would you prevent these factorsfrom causing harm?

Record your answer in your science journal.

Chapter 3

• Describe the process of succession.

• Contrast primary and secondary succession.

• Explain how mature communities develop.

Objectives

Section 2 Ecological Succession

Chapter 3

Regrowth of a Forest

• Succession The replacement of one type of community by another at a single place over a period of time is called succession.

• The regrowth of a forest after a forest fire is an example of succession.

• Succession takes place in all communities, not just those affected by disturbances such as forest fires.

Section 2 Ecological Succession

Chapter 3

Primary Succession

• Sometimes, a small community starts to grow in an area where other organisms had not previously lived.

• Over a very long time, a series of organisms live and die on the rock. The rock is slowly transformed into soil. This process is called primary succession.

Section 2 Ecological Succession

Chapter 3 Section 2 Ecological Succession

Chapter 3

Secondary Succession

• Sometimes, a community is disturbed in some way. If soil is left intact, the original community may regrow through a series of stages called secondary succession.

Section 2 Ecological Succession

Chapter 3 Section 2 Ecological Succession

Chapter 3

Ecological Succession

Click below to watch the Visual Concept.

Visual Concept

Section 2 Ecological Succession

Chapter 3

Mature Communities and Biodiversity

• In the early stages of succession, only a few species grow in an area. As a community matures, it may be dominated by a well-adapted, slow-growing climax species.

• The variety of species that are present in an area is referred to as biodiversity. Having biodiversity helps communities lessen the impact and spread of disturbances such as insect invasions.

Section 2 Ecological Succession

Chapter 3

Mature Communities and Biodiversity, continued• Mature communities tend to have biodiversity. A

mature community simply has organisms that are well adapted to live together in the same area over time.

Section 2 Ecological Succession

Chapter 3

Concept MappingUse the terms below to complete the concept map on the next slide.

water cycle carbondecomposition combustion condensation carbon cycle precipitation photosynthesis

Cycles in Nature

Chapter 3 Cycles in Nature

Chapter 3 Cycles in Nature